Παραπομπή APA

Ryan, C. (2006). Recreational tourism: Demand and impacts. Viva books.

Παραπομπή Chicago Style

Ryan, Chris. Recreational Tourism: Demand and Impacts. New Delhi: Viva books, 2006.

Παραπομπή MLA

Ryan, Chris. Recreational Tourism: Demand and Impacts. Viva books, 2006.